I'm surprised I haven't seen QoS mentioned! If you're teaching college students, you might want to go over stuff that directly relates to what they're doing at home, or misconceptions they might make in a small WAN/ISP environment. *Why disabling ICMP doesn't increase security and only hurts the web* *(path MTU discovery, diagnostics) *How NAT breaks end-to-end connectivity (fun one..., took me hours to explain to an old boss why doing NAT at the ISP level was horrendously wrong) *Not to be afraid of ACLs on an edge router. Understanding what does/doesn't affect cpu utilization *Layer 3 Switch vs Router. Old concepts like switch vs router need to be clarified... *When vendors and numbers lie ;) aka *oversubscription*! *MAC is not security *Irrelevant security concepts (smurf attacks, ping of death). More focus should be on real modern day security concerns, like layer 7 exploits, router software 0days, VLAN hopping, and UDP floods and BGP spoofing. This might be a good place to explain why downloading IOS firmware from thepiratebay is a bad idea :) This is just coming from a sysadmin who likes to play with network gear and once endured college networking classes. Thanks! Andreas On Wed, Feb 15, 2012 at 1:47 PM, John Kristoff <jtk@cymru.com> wrote:
Hi friends,
As some of you may know, I occasionally teach networking to college students and I frequently encounter misconceptions about some aspect of networking that can take a fair amount of effort to correct.
For instance, a topic that has come up on this list before is how the inappropriate use of classful terminology is rampant among students, books and often other teachers. Furthermore, the terminology isn't even always used correctly in the original context of classful addressing.
I have a handful of common misconceptions that I'd put on a top 10 list, but I'd like to solicit from this community what it considers to be the most annoying and common operational misconceptions future operators often come at you with.
I'd prefer replies off-list and can summarize back to the list if there is interest.
John